Dual coil transaction card

ABSTRACT

A secure transaction card does not interact with an interrogating radio frequency field without user interaction. The user interaction may include pressing on the card to cause a smartcard chip to connect to a coil on the card. The user interaction may also include exposing the card to light, motion, touch, or the like. Control of the secure transaction card may be active or passive.

FIELD The present invention relates generally to transaction cards, andmore specifically to transaction cards with smartcard chips. BACKGROUND

A transaction card may include a smartcard chip and a coil. Thesmartcard chip is typically connected to the coil so that when thetransaction card is in the presence of an interrogating radio frequencyfield, the transaction card receives power and transfers information tothe device emitting the interrogating radio frequency field.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exploded view of a secure transaction card;

FIG. 2 shows a top view of the secure transaction card of FIG. 1;

FIG. 3 shows a sectional view of the secure transaction card of FIG. 1;

FIG. 4 shows a detail view of a portion of the transaction card shown inFIG. 1;

FIG. 5 shows a top view of the secure transaction card of FIG. 1;

FIG. 6 shows a second sectional view of the secure transaction card ofFIG. 1;

FIG. 7 shows a second detail view of a portion of the transaction cardshown in FIG. 1;

FIG. 8 shows an exploded view of a secure transaction card;

FIG. 9 shows a top view of the secure transaction card of FIG. 8;

FIG. 10 shows a sectional view of the secure transaction card of FIG. 8;

FIG. 11 shows a detail view of a portion of the transaction card shownin FIG. 8;

FIG. 12 shows an exploded view of a secure transaction card;

FIG. 13 shows a top view of the secure transaction card of FIG. 12;

FIG. 14 shows a sectional view of the secure transaction card of FIG.12;

FIG. 15 shows a detail view of a portion of the transaction card shownin FIG. 12;

FIG. 16 shows an exploded view of a secure transaction card;

FIG. 17 shows a top view of the secure transaction card of FIG. 16;

FIG. 18 shows a sectional view of the secure transaction card of FIG.16;

FIG. 19 shows a detail view of a portion of the transaction card shownin FIG. 16;

FIGS. 20-25 show diagrams of secure transaction cards with passivecontrol;

FIG. 26 shows an exploded view of a secure transaction card with activecontrol;

FIG. 27 shows a top view of the secure transaction card of FIG. 26;

FIGS. 28 and 29 show diagrams of secure transaction cards with activecontrol;

FIG. 30 shows a diagram of a control circuit used in a securetransaction card;

FIG. 31 shows an exploded view of a secure transaction card with activecontrol;

FIG. 32 shows a diagram of a secure transaction card with activecontrol;

FIG. 33 shows an exploded view of a secure transaction card with activecontrol;

FIG. 34 shows a top view of the secure transaction card of FIG. 32; and

FIGS. 35 and 36 show flowcharts of methods in accordance with variousembodiments of the present invention.

DESCRIPTION OF EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawings that show, by way of illustration, variousembodiments of an invention. These embodiments are described insufficient detail to enable those skilled in the art to practice theinvention. It is to be understood that the various embodiments of theinvention, although different, are not necessarily mutually exclusive.For example, a particular feature, structure, or characteristicdescribed in connection with one embodiment may be implemented withinother embodiments without departing from the scope of the invention. Inaddition, it is to be understood that the location or arrangement ofindividual elements within each disclosed embodiment may be modifiedwithout departing from the scope of the invention. The followingdetailed description is, therefore, not to be taken in a limiting sense,and the scope of the present invention is defined only by the appendedclaims, appropriately interpreted, along with the full range ofequivalents to which the claims are entitled. In the drawings, likenumerals refer to the same or similar functionality throughout theseveral views.

FIG. 1 shows an exploded view of a secure transaction card. Securetransaction card 100 includes multiple layers 110, 120, 130 that arelaminated together, and also includes smartcard chip 140. Three layersare shown in FIG. 1; however, any number of layers may be includedwithout departing from the scope of the present invention. Further, thelayers may be of any thickness and any relative thickness. For example,some layers may be thicker than others.

Examples of smartcard chips are the “SmartMX” controllers sold by NXPSemiconductors N.V. of Eindhoven, The Netherlands. In some embodiments,smartcard chip 140 has an ISO/IEC 7816 compatible interface thatcommunicates using a “contact” interface, although this is not alimitation of the present invention. Further, in some embodiments,smartcard chip 140 includes a near field communications (NFC) radio (notshown) that includes an ISO/IEC 14443 “contactless” interface. Smartcardchips that include both a “contact” interface and a “contactless”interface are referred to herein as “dual-interface” smartcard chips.

In some embodiments, smartcard chip 140 is a dual-interface smartcardchip, and secure transaction card 100 may operate as either a contactcard, or a contactless card. When secure transaction card 100 isoperating as a contact card, electrical contacts on top of smartcardchip 140 provide electrical connectivity after secure transaction card100 is inserted in a reader. When secure transaction card 100 isoperating as a contactless card, smartcard chip 140 is powered usingenergy inductively coupled to secure transaction card 100 when the cardis placed in the presence of an interrogating radio frequency field.

A first layer of secure transaction card 100 is shown at 120. Layer 120includes an electrically conductive coil 122, a recessed portion 124,and coil contacts 126, 128. Coil 122 may have any number of turns. Theends of coil 122 are electrically connected to coil contacts 126, 128.Coil contacts 126, 128 are typically metal contacts that may makecontact with antenna contacts on the underside of smartcard chip 140(not shown in FIG. 1). In some embodiments, coil 122 is on the topsurface of layer 120 as shown. In other embodiments, coil 122 isembedded within layer 120. For example, layer 120 may have sublayers,and coil 122 may be embedded within or between sublayers. In stillfurther embodiments, coil 122 is on a bottom surface of layer 120.

Layer 110 is above layer 120. The term “above” is a relative term. Forexample, layer 110 may be considered to be below layer 120 when securetransaction card 100 is turned over. Accordingly, the terms “above,”“below,” and the like are meant to describe relative orientations, andare not meant to describe an absolute orientation. Layer 110 includeshole 112. Hole 112 is sized to receive smartcard chip 140 and to allowthe electrical contacts on top of smartcard chip 140 to be exposed onthe surface of secure transaction card 100. Layer 130 is below 120.

Layers may be made of plastic, polymers, or any other material. Forexample, in some embodiments, various layers of transaction card 100 aremade of polyvinyl chloride, polyethylene terephthalate based polymers,acrylonitrile butadiene styrene or polycarbonate. In other embodiments,various layers of transaction card 100 are made of organic materialscommonly used to manufacture printed circuit boards. Secure transactioncards described herein may be made of any type of material withoutdeparting from the scope of the present invention.

Smartcard chip 140 is shown as a single monolithic element in FIG. 1;however, in some embodiments, smartcard chip 140 includes an integratedcircuit die, a substrate, bonding wires, encapsulating material, andmore. The packaging of smartcard chip 140 is not a limitation of thepresent invention.

In operation, smartcard chip 140 is not always in electrical contactwith coil 122. For example, in some embodiments, smartcard chip 140 issuspended above coil contacts 126, 128 such that unless securetransaction card 100 is pressed in the vicinity of smartcard chip 140,or smartcard chip 140 is pressed directly, no connection to the coil ismade. This keeps secure transaction card 100 from responding to a readerunless a user presses on the card. Various embodiments requiring userintervention are further described below.

FIG. 2 shows a top view of the secure transaction card of FIG. 1.Smartcard chip 140 is shown with electrical contacts exposed on asurface of the card. Some embodiments are only contactless and do nothave exposed contacts. Examples of contactless-only embodiments aredescribed further below.

Secure transaction card 100 may have any dimensions, and thosedimensions may or may not comply with a standard such as ISO/IEC 7810.For example, in some embodiments, the dimensions of secure transactioncard are 3.370 in×2.125 in×0.030 thick, although this is not alimitation of the present invention.

FIG. 3 shows a sectional view of the secure transaction card of FIG. 1.The sectional view in FIG. 3 shows smartcard chip 140 and at least someof the layers making up the card. In some embodiments, securetransaction card 100 may include many more than three layers. Forexample, secure transaction card 100 may include additional plasticlayers, printed layers with branding information, and outermostprotective layers.

FIG. 4 shows a detail view of a portion of the transaction card shown inFIG. 1. A cross section of smartcard chip 140 is shown in FIG. 4, as arecoil 122, coil contacts 126, 128, antenna contacts 142, 144, and spring310. In embodiments represented by FIG. 4, coil 122 is embedded withinlayer 120, and layer 130 is not shown. As shown in FIG. 4, spring 310 isa standoff mechanism to keep antenna contacts 142, 144 on smartcard chip140 from contacting the two coil contacts 126, 128 unless smartcard chip140 is pressed towards the first layer 120.

Spring 310 is shown as a coil spring contacting smartcard chip 140 nearthe center, but the various embodiments of the invention are not solimited. For example, in some embodiments, the standoff mechanismsupports smartcard chip 140 around the periphery, on the sides, or onthe corners. Also for example, in some embodiments, a spring type otherthan a coil spring is used for the standoff mechanism.

In operation, coil 122 is not connected to smartcard chip 140 unlesssmartcard chip 140 is pressed. Accordingly, even when in the presence ofan interrogating radio frequency field, smartcard chip 140 will notcommunicate with a reader without user intervention. This increases thesecurity of secure transaction card 100, in part because the smartcardchip cannot be interrogated without the user's consent.

FIG. 5 shows a top view of the secure transaction card of FIG. 1. Thetop view shown in FIG. 5 is the same as the top view shown in FIG. 2with the exception that secure transaction card 100 has been rotated 90degrees counterclockwise in FIG. 5.

FIG. 6 shows a second sectional view of the secure transaction card ofFIG. 1. The section shown in FIG. 6 is defined in FIG. 5. The section istaken through smartcard chip 140 at an angle that does not slice throughthe antenna contacts on the underside of smartcard chip 140.

FIG. 7 shows a second detail view of a portion of the transaction cardshown in FIG. 1. A cross section of smartcard chip 140 is shown in FIG.7, as are coil 122, coil contact 128, antenna contact 144, andcantilever springs 710 and 712. In embodiments represented by FIG. 7,coil 122 is embedded within layer 120, and layer 130 is not shown. Asshown in FIG. 7, cantilever springs 710 and 712 are a standoff mechanismto keep antenna contacts 142, 144 on smartcard chip 140 from contactingthe two coil contacts 126, 128 unless smartcard chip 140 is pressedtowards the first layer 120.

In some embodiments, cantilever springs 710 and 712 are supported bylayer 120 and extend beneath smartcard chip 140. For example, in someembodiments, layer 120 is plastic, and cantilever springs 710, 712 areformed as part of layer 120. In other embodiments, layer 120 is formedof sublayers, and one or more of the sublayers is extended to formcantilever springs 710, 712.

When at rest, cantilever springs 710, 712 cause smartcard chip 140 to besuspended above coil contacts 126, 128. Accordingly, in operation, coil122 is not connected to smartcard chip 140 unless smartcard chip 140 ispressed, and smartcard chip 140 will not communicate with a readerwithout user intervention, even when in the presence of an interrogatingradio frequency field. This increases the security of secure transactioncard 100, in part because the smartcard chip cannot be interrogatedwithout the user's consent.

FIG. 8 shows an exploded view of a secure transaction card. Securetransaction card 800 includes multiple layers 810, 120, 130 that arelaminated together, and also includes smartcard chip 840. Three layersare shown in FIG. 8; however, any number of layers may be includedwithout departing from the scope of the present invention. Further, thelayers may be of any thickness and any relative thickness. For example,some layers may be thicker than others.

In the example provided in FIG. 8, smartcard chip 840 does not includeelectrical contacts that will be exposed on a surface of the card. Insome embodiments, smartcard chip 840 is a contactless-only chip and doesnot include an ISO/IEC 7816 interface. In other embodiments, smartcardchip 840 is a dual-interface smartcard chip that includes both ISO/IEC7816 and ISO/IEC 14443 interfaces, and the ISO WC 7816 interface is notexposed outside the transaction card.

First layer 120 of secure transaction card 800 is described above withreference to FIG. 1. Layer 120 includes an electrically conductive coil122, a recessed portion 124, and coil contacts 126, 128. Second layer810 is above layer 120. The term “above” is a relative term. Forexample, layer 810 may be considered to be below layer 120 when securetransaction card 800 is turned over. Layer 810 differs from layer 110(FIG. 1), in that layer 810 does not include a hole to expose smartcardchip 840 on a surface of the transaction card. Layer 130 is below 120.

Smartcard chip 840 is shown as a single monolithic element in FIG. 8;however, in some embodiments, smartcard chip 840 includes an integratedcircuit die, a substrate, bonding wires, encapsulating material, andmore. The packaging of smartcard chip 840 is not a limitation of thepresent invention.

In operation, smartcard chip 840 is not always in electrical contactwith coil 122. For example, in some embodiments, smartcard chip 840 issuspended above coil contacts 126, 128 such that unless securetransaction card 800 is pressed in the vicinity of smartcard chip 840,no connection to the coil is made. This keeps secure transaction card800 from responding to a reader unless a user presses on the card.Various embodiments requiring user intervention are further describedbelow.

FIG. 9 shows a top view of the secure transaction card of FIG. 8. Area812 on the surface of secure transaction card 800 marks the vicinity ofsmartcard chip 840. When a user presses on area 812, contact is madebetween smartcard chip 840 and coil 122, and when in the presence of aninterrogating radio frequency field, smartcard chip 840 may receivepower and respond to a reader. Area 812 may be marked or indicated onthe surface of secure transaction card 800 in any manner. For example,in some embodiments, a recognizable icon is placed in area 812, to thata user knows to press in that location. In other embodiments, text isplaced in or near area 812 to alert the user to press on area 812 toeffect a transaction.

FIG. 10 shows a sectional view of the secure transaction card of FIG. 8.The sectional view of FIG. 10 is similar to the sectional view of FIG.3.

FIG. 11 shows a detail view of a portion of the transaction card shownin FIG. 8. A cross section of smartcard chip 840 is shown in FIG. 11, asare layers 810, 120, 130, coil 122, coil contacts 126, 128, and antennacontacts 142, 144. In embodiments represented by FIG. 11, coil 122 andcoil contacts 126, 128 are on the bottom of layer 120. As shown in FIG.11, smartcard chip 840 is bonded to the bottom of layer 810, and issuspended above coil contacts 126 and 128. The bonding of smartcard chip840 to layer 810 and the size of recessed portion 124 form a standoffmechanism that keeps antenna contacts 142, 144 on smartcard chip 840from contacting the two coil contacts 126, 128 unless smartcard chip 840is pressed towards the first layer 120.

In some embodiments, the standoff mechanism shown in FIG. 11 is combinedwith standoff mechanisms described with reference to previous figures.For example, coil springs, cantilever springs or other types of springsmay be placed in recessed portion 124 to aid in suspending smartcardchip 840 above coil contacts 126, 128.

FIG. 11 shows smartcard chip 840 being wholly within recessed portion124, although this is not a limitation of the present invention. Forexample, in some embodiments, layer 810 includes a recessed portion, andall or a portion of smartcard chip 840 is within the recessed portion oflayer 810.

During manufacture of secure transaction card 800, the various layersmay be formed separately and smartcard chip 840 is bonded to one or morelayers prior to the layers being laminated together. Similarly, coil 122and coil contacts 126, 128 may be formed on or in layer 120 prior tolaminating the various layers together.

In operation, coil 122 is not connected to smartcard chip 840 unlesssecure transaction card 800 is pressed in the vicinity of smartcard chip840. Accordingly, even when in the presence of an interrogating radiofrequency field, smartcard chip 840 will not communicate with a readerwithout user intervention. This increases the security of securetransaction card 800, in part because the smartcard chip cannot beinterrogated without the user's consent.

FIG. 12 shows an exploded view of a secure transaction card. Securetransaction card 1200 includes multiple layers 1210, 1220, 1230 that arelaminated together, and also includes smartcard chip 1240. Three layersare shown in FIG. 12; however, any number of layers may be includedwithout departing from the scope of the present invention. Further, thelayers may be of any thickness and any relative thickness. For example,some layers may be thicker than others.

In the example provided in FIG. 12, smartcard chip 1240 does not includeelectrical contacts that will be exposed on a surface of the card. Insome embodiments, smartcard chip 1240 is a contactless-only chip anddoes not include an ISO/IEC 7816 interface. In other embodiments,smartcard chip 1240 is a dual-interface smartcard chip that includesboth ISO/IEC 7816 and ISO/IEC 14443 interfaces, and the ISO WC 7816interface is not exposed outside the transaction card.

First layer 1220 of secure transaction card 1200 is similar, but notidentical, to layer 120 described above with reference to FIG. 1. Likelayer 120 of FIG. 1, layer 1220 includes an electrically conductive coil122, a recessed portion 124, and coil contacts 126, 128. Layer 1220 alsoincludes electrical contacts 1226 and 1228 coupled to coil 122.

In some embodiments, smartcard chip 1240 is electrically bonded to layer1220 such that the antenna contacts on the underside of smartcard chip1240 are electrically bonded to coil contacts 126 and 128.

In some embodiments, electrical contacts 1226, 1228 are in series withcoil 122, such that when an electrical connection is made betweencontacts 1226, 1228, smartcard chip 1240 is connected to coil 122 and isable to receive power and communicate when coil 122 is in the presenceof an interrogating radio frequency field. Similarly, when there is noelectrical connection between contacts 1226, 1228, coil 122 is an opencircuit and smartcard chip is 840 does not receive power and cannotcommunicate even when coil 122 is in the presence of an interrogatingradio frequency field.

Second layer 1210 is above layer 1220. Second layer includes aconnection mechanism (not shown in FIG. 12) that can conditionallyelectrically connect contacts 1226, 1228 in response to a user pressingor pinching secure transaction card 1200 in the vicinity of contacts1226, 1228. An example connection mechanism is shown on layer 1230.Connection mechanism 1232 is in the form of a conductive strip bonded tolayer 1230. In some embodiments, contacts similar to 1226, 1228 alsoexist on the bottom of layer 1220, and when secure transaction card 1200is pressed or pinched in the vicinity of contacts 1226, 1228, coil 122is closed and electrically connected to smartcard chip 1240.

In operation, smartcard chip 1240 and coil 122 do not always form acompleted circuit. For example, in some embodiments, even thoughsmartcard chip 1240 is always in contact with coil 122, coil 122 mayinclude an open circuit when contacts 1226, 1228 are not electricallyconnected. When a user presses secure transaction card 1200 in thevicinity of contacts 1226, 1228, contact is made, and smartcard chip1240 can receive power and communicate with a reader when in thepresence of an interrogating radio frequency field. This keeps securetransaction card 1200 from responding to a reader unless a user presseson the card.

FIG. 13 shows a top view of the secure transaction card of FIG. 12. Area1310 on the surface of secure transaction card 1200 marks the vicinityof contacts 1226, 1228. When a user presses on area 1310, contact ismade between contacts 1226, 1228, and when in the presence of aninterrogating radio frequency field, smartcard chip 1240 may receivepower and respond to a reader. Area 1310 may be marked or indicated onthe surface of secure transaction card 1200 in any manner. For example,in some embodiments, a recognizable icon is placed in area 1310, so thata user knows to press in that location. In other embodiments, text isplaced in or near area 1310 to alert the user to press on area 1310 toeffect a transaction.

In some embodiments, transaction card 1200 includes multiple locationsat which a user can or must press in order to effect a transaction. Forexample, multiple locations may be indicated on one side of transactioncard 1200, or multiple locations may be indicated on both sides oftransaction card 1200.

FIG. 14 shows a sectional view of the secure transaction card of FIG.12. The sectional view is in the vicinity of contacts 1226, 1228 (FIG.12). A detail of view of that portion of the card is shown in FIG. 15.

FIG. 15 shows a detail view of a portion of the transaction card shownin FIG. 12. A cross section of smartcard chip coil 122 is shown in FIG.15, as are layers 1210, 1220, 1230, contacts 1226, 1228, and conductivestrip 1232. FIG. 15 also shows contacts 1236, 1238 and conductive strip1212, which are not shown in FIG. 12. In embodiments represented by FIG.15, coil 122 is embedded within layer 1220, and contacts 1226, 1228 arewithin a recessed portion of layer 1220. Conductive strip 1212 is bondedto the underside of layer 1210. Likewise, contacts 1236, 1238 are withina recessed portion of the underside of layer 1220, and conductive strip1232 is bonded to the top of layer 1230. The bonding of conductivestrips 1212, 1232 to layers 1210, 1230 and the size of the recessedportions housing contacts 1226, 1228, 1236, 1238 form a standoffmechanism that keeps coil 122 from forming a closed circuit withsmartcard chip 1240 unless secure transaction card 1200 is pressedtowards the first layer 1220 in the vicinity of area 1310. Circuitdiagrams for various interconnection embodiments are described furtherbelow.

In operation, a closed circuit including coil 122 and smartcard chip1240 is not formed unless secure transaction card 1200 is pressed in thevicinity of area 1310. Accordingly, even when in the presence of aninterrogating radio frequency field, smartcard chip 1240 will notcommunicate with a reader without user intervention. This increases thesecurity of secure transaction card 1200, in part because the smartcardchip cannot be interrogated without the user's consent.

FIG. 16 shows an exploded view of a secure transaction card. Securetransaction card 1600 includes multiple layers 1610, 1620, 1630 that arelaminated together, and also includes smartcard chip 1240. Three layersare shown in FIG. 12; however, any number of layers may be includedwithout departing from the scope of the present invention. Further, thelayers may be of any thickness and any relative thickness. For example,some layers may be thicker than others.

First layer 1620 of secure transaction card 1600 is similar, but notidentical, to layer 1220 described above with reference to FIG. 12. Likelayer 1220 of FIG. 12, layer 1620 includes an electrically conductivecoil 122, a recessed portion 124, and coil contacts 126, 128. Layer 1220also includes electrical contacts 1626 and 1628 coupled to coil 122.

In some embodiments, smartcard chip 1240 is electrically bonded to layer1620 such that the antenna contacts on the underside of smartcard chip1240 are electrically bonded to coil contacts 126 and 128.

In some embodiments, electrical contacts 1626, 1628 are in series withcoil 122, such that when an electrical connection is made betweencontacts 1626, 1628, smartcard chip 1240 is connected to coil 122 and isable to receive power and communicate when coil 122 is in the presenceof an interrogating radio frequency field. In other embodiments,electrical contacts 1626, 1628 are in parallel with coil 122 such thatan electrical connection is made between contacts 1626, 1628, theantenna terminals of smartcard chip 1240 are effectively shorted,thereby disabling any contactless communications.

Second layer 1610 is above layer 1620. Second layer 1620 includesthrough vias 1616, 1618 that make connection to contacts 1626, 1628. Inoperation, smartcard chip 1240 and coil 122 do not always form acompleted circuit. For example, in some embodiments, even thoughsmartcard chip 1240 is always in contact with coil 122, coil 122 mayinclude an open circuit when contacts 1626, 1628 are not electricallyconnected. In these embodiments, when a user touches vias 1616, 1618,contact is made, and smartcard chip 1240 can receive power andcommunicate with a reader when in the presence of an interrogating radiofrequency field. Also for example, coil 122 may be detuned such thatwithout a user touching vias 1616, 1618, coil 122 cannot generatesufficient voltage to power smartcard chip 1240. In these embodiments,when a user touches vias 1616, 1628, coil 122 becomes properly tuned,and contactless communications can take place.

FIG. 17 shows a top view of the secure transaction card of FIG. 16. Insome embodiments, when a user touches vias 1616, 1618, contact is madebetween contacts 1626, 1628, and when in the presence of aninterrogating radio frequency field, smartcard chip 1240 may receivepower and respond to a reader. In other embodiments, a user touchingvias 1616, 1618 either tunes or detunes coil 122 to either allowcommunications or disallow communications between smartcard chip 1240and a reader device.

FIG. 18 shows a sectional view of the secure transaction card of FIG.16. The sectional view of FIG. 18 shows the area of secure transactioncard 1600 that includes contacts 1626, 1628, and vias 1616, 1618.

FIG. 19 shows a detail view of a portion of the transaction card shownin FIG. 16. The detail view shown in FIG. 19 includes layers 1610, 1620,1630, contacts 1626, 1628, and vias 1616, 1618. As can be seen in FIG.19, if a user touches vias 1616, 1618, then a connection through auser's skin is made between contacts 1626, 1628. Circuit diagrams forvarious interconnection embodiments are described further below.

FIGS. 20-25 show diagrams of secure transaction cards with passivecontrol. FIG. 20 shows a circuit diagram that represents the electricalconnections of secure transaction cards 100 (FIGS. 1) and 800 (FIG. 8).Smartcard chip 2040 may be any of the smartcard chips described herein.As shown in FIG. 20, smartcard chip 2040 is not connected to coil 122unless smartcard chip 2040 is pressed directly or unless the securetransaction card is pressed in the vicinity of smartcard chip 2040.

FIG. 21 shows a circuit diagram demonstrating the operation of at leastone embodiment represented by secure transaction card 1200 (FIG. 12). Inthese embodiments, one set of contacts 1226, 1228 are in series withcoil 122, and one conductive strip 1212 makes an electrical connectionbetween contacts 1226 and 1228 when the secure transaction card ispressed in the vicinity of conductive strip 1212.

FIG. 22 shows a circuit diagram demonstrating the operation of at leastone embodiment represented by secure transaction card 1200 (FIG. 12). Inthese embodiments, two set of contacts (1226, 1228) and (1236, 1238) arein series with coil 122, and are in parallel with each other. Oneconductive strip 1212 makes an electrical connection between contacts1226 and 1228 when the secure transaction card is pressed in thevicinity of conductive strip 1212, and another conductive strip 1232makes an electrical connection between contacts 1236, 1238 when thesecure transaction card is pressed in the vicinity of conductive strip1232. If either set of contacts are closed, then a connection is madebetween smartcard chip 1240 and coil 122.

In some embodiments, conductive strips 1212 and 1232 are on oppositesides of the secure transaction card as shown in FIGS. 12 and 15. Inother embodiments, conductive strips and their associated contacts areon the same side of the secure transaction card. In still furtherembodiments, conductive strips and their associated contacts are onopposing sides of the card, but they are in different locations (e.g.,on different corners of the card).

FIG. 23 is similar to FIG. 22 except that two separate coils exist. Whencontacts 1226, 1228 are electrically connected, smartcard chip 1240 isconnected to coil 122B. When contacts 1236, 1238 are electricallyconnected, smartcard chip 1240 is connected to coil 122A. In someembodiments, the electrical specifications of coils 122A and 122B aresufficiently similar such that smartcard chip 1240 can operatingregardless which one is used. This provides redundancy that may enhancereliability.

FIG. 24 shows a circuit diagram demonstrating the operation of at leastone embodiment represented by secure transaction card 1600 (FIG. 16). Inthese embodiments, one set of contacts (vias 1616, 1228) are in serieswith coil 122. A user may make an electrical connection between thecontacts when the secure transaction card is touched in the vicinity ofvias 1616, 1618.

FIG. 25 shows a circuit diagram demonstrating the operation of at leastone embodiment represented by secure transaction card 1600 (FIG. 16). Inthese embodiments, one set of contacts (vias 1616, 1228) are in parallelwith coil 122. A user may make an electrical connection between thecontacts when the secure transaction card is touched in the vicinity ofvias 1616, 1618. By touching vias 1616, 1618, a user may modify thetuning of coil 122, thereby allowing or disallowing the operation ofsmartcard chip 1240.

FIG. 26 shows an exploded view of a secure transaction card with activecontrol. Secure transaction card 2600 includes multiple layers 2610,2620, 2630 that are laminated together, and also includes smartcard chip2640. Three layers are shown in FIG. 26; however, any number of layersmay be included without departing from the scope of the presentinvention. Further, the layers may be of any thickness and any relativethickness. For example, some layers may be thicker than others. In theexample provided in FIG. 26, smartcard chip 2640 does not includeelectrical contacts that will be exposed on a surface of the card. Insome embodiments, smartcard chip 2640 is a contactless-only chip anddoes not include an ISO/IEC 7816 interface. In other embodiments,smartcard chip 2640 is a dual-interface smartcard chip that includesboth ISO/IEC 7816 and ISO/IEC 14443 interfaces, and the ISO WC 7816interface is not exposed outside the transaction card.

First layer 2620 of secure transaction card 2600 is similar, but notidentical, to layer 1220 described above with reference to FIG. 12. Likelayer 1220 of FIG. 12, layer 2620 includes an electrically conductivecoil 122. Layer 2620 also includes a second electrically conductive coil2622, and control circuit 2624.

In some embodiments, smartcard chip 2640 is electrically bonded to layer2620 such that the antenna contacts on the underside of smartcard chip2640 are electrically bonded to coil contacts beneath the smartcardchip.

Second layer 2610 is above layer 2620. Second layer 2610 includes asensor 2612 that is able to sense an environmental attribute, such aslight, motion, sound, touch, proximity, a biometric, or the like. Sensor2612 is coupled to control circuit 2624 such that control circuit canread the state of sensor 2612, and conditionally allow or disallowcommunications by smartcard chip 2640 based on the state of theenvironmental attribute. Layer 2630 is below layer 2620.

In operation, control circuit 2642 receives power from electricallyconductive coil 2622 when in the presence of an interrogating radiofrequency field. Control circuit 2622 can read the state of sensor 2612and either allow contactless communications or disallow contactlesscommunications. In some embodiments, control circuit 2642 allowscontactless communications by conditionally coupling smartcard chip 2640to coil 122 in response to an environmental attribute. In otherembodiments, control circuit 2642 allows contactless communications bymodifying a tuning element coupled to coil 122. In these embodiments,coil 122 is said to be “detuned” until control circuit 2624 “tunes” it.When coil 122 is detuned, smartcard chip is not able to draw power fromcoil 122. Various coil connection embodiments and tuning embodiments aredescribed more fully below.

FIG. 27 shows a top view of the secure transaction card of FIG. 26.Secure transaction card 2600 includes sensor 2612 exposed on a surface.In operation, a user may interact with secure transaction card 2600 bytouching sensor 2612, exposing sensor 2612 to light, subjecting securetransaction card 2600 to motion, or the like. In some embodiments,secure transaction card 2600 may not perform a contactless transactionunless and until a user interacts with sensor 2612 in a prescribedfashion. This increases security because a reader cannot interact with asmartcard chip in secure transaction card 2600 without the user'sconsent.

FIGS. 28 and 29 show diagrams of secure transaction cards with activecontrol. FIG. 28 includes smartcard chip 2640, control circuit 2624,sensor 2612, and electrically conductive coils 2622, 122. Controlcircuit is coupled to receive power from electrically conductive coil2622. When placed in the presence of an interrogating radio frequencyfield, control circuit 2642 draws power from coil 2622, and then makes adecision whether to couple smartcard chip 2640 to coil 122. If smartcardchip 2640 is coupled to coil 122, then contactless communications cantake place to effect a transaction, and if smartcard 2640 is not coupledto coil 122, then contactless communication cannot take place and atransaction cannot be effected.

Control circuit 2624 may use any criteria, or environmental attribute,or sequence of sensor states in the decision whether to couple smartcardchip 2640 to coil 122 to effect a transaction. For example, in someembodiments, sensor 2612 is a light sensor. In these embodiments,control circuit 2624 may only effect a transaction when light above acertain threshold is sensed by sensor 2612. This may thwart attempts bya reader to interact with smartcard chip 2640 when smartcard chip 2640is in a user's wallet or purse. In these embodiments, secure transactioncard 2600 will only allow smartcard chip 2640 to interact with a readerwhen the card has been taken out from a user's wallet or purse and hasbeen exposed to light. Further, in some embodiments, control circuit2624 may only effect a transaction when a particular sequence of lightstates is detected. For example, a user may be required to block lightfrom impinging on the sensor when first placing the secure transactioncard in the interrogating radio frequency field, followed by allowinglight to impinge on the sensor.

Also for example, in some embodiments, sensor 2612 senses human touch.In these embodiments, control circuit 2642 may only effect a transactionwhen a user touches the sensor. This may also thwart nefarious readerattempts at communications. In still further examples, sensor 2612 maybe a motion sensor and a transaction may not be effected unless the cardundergoes a certain motion, sensor 2612 may be a biometric sensor and atransaction may not be effected unless a particular biometric (e.g.,finger print) is sensed, or sensor 2612 may be a microphone and atransaction may not be effected unless the card receives a particularaudio sequence (e.g., voice commands or user voice recognition). Sensor2612 may sense any environmental attribute and control circuit 2642 mayallow or disallow contactless communications based on any state of anyenvironmental attribute or sequence of environmental attributes withoutdeparting from the scope of the present invention.

FIG. 28 shows control circuit 2624 controlling a switch 2810 with acontrol signal 2812 to conditionally couple smartcard chip 2640 to coil122. In some embodiments, switch 2810 may be a metal oxide semiconductortransistor that is connected as a pass transistor. In these embodiments,control signal 2812 may be coupled to a gate node of the transistor toturn the transistor on and off under the direction of control circuit2624. Switch 2810 may be implemented in any manner using any suitablecomponents without departing from the scope of the present invention.

FIG. 29 includes many of the same elements as FIG. 28, however, ratherthan switch 2810, FIG. 29 includes tuning circuit 2910. Embodimentsrepresented by FIG. 29 tune or detune coil 122 to allow or disallowcontactless communications. For example in some embodiments, tuningcircuit 2910 includes additional capacitance and/or inductance, whichwhen in parallel with coil 122, detunes coil 122 to the point thatsmartcard chip 2640 cannot draw sufficient power from coil 122 tooperate. If control circuit 2624 determines that a transaction should beeffected, then through the operation of control signal 2812, controlcircuit 2624 may tune coil 122 by removing the excess capacitance and/orinductance present in tuning circuit 2910. When coil 122 is tuned, it isresonant at the frequency of the interrogating radio frequency field andsmartcard chip 2640 may draw sufficient power from coil 122 to operate.

FIG. 30 shows a diagram of a control circuit used in a securetransaction card. Control circuit 2624 includes controller 3010, memory3020, and rectifier 3030. Control circuit 2624 may include many moreelements without departing from the scope of the present invention.

Controller 3010 may be any type of controller or processor capable ofexecuting instructions stored in memory 3020 and capable of interfacingwith the various components shown in FIG. 30. For example, controller3010 may be a microprocessor, a digital signal processor, an applicationspecific processor, or the like. In some embodiments, controller 3010 isa component within a larger integrated circuit such as a system on chip(SOC) application specific integrated circuit (ASIC).

Memory 3020 may include any type of memory device. For example, memory3020 may include volatile memory such as static random access memory(SRAM), or nonvolatile memory such as FLASH memory. Memory 3020 isencoded with (or has stored therein) one or more software modules (orsets of instructions), that when accessed by controller 3010, result incontroller 3010 performing various functions.

Rectifier 3030 is coupled to a coil to receive power when the coil is inthe presence of an interrogating radio frequency field. For example, insome embodiments, rectifier 3030 is coupled to coil 2622 (FIGS. 26, 28,29). In these embodiments, when the secure transaction card is in thepresence of an interrogating radio frequency field, rectifier 3030rectifies a voltage on coil 2622, and provides power to the remainder ofcontrol circuit 2642.

In operation, control circuit 2642 starts to function when the securetransaction card is in the presence of an interrogating radio frequencyfield and power is supplied to controller 3010. Controller 3010 readsinstructions encoded in memory 3020, and performs actions in responsethereto. In some embodiments, the actions include reading the state ofsensor 2612 and driving control signals on node 2812 to either allow ordisallow a contactless transaction.

FIG. 31 shows an exploded view of a secure transaction card with activecontrol. Secure transaction card 3100 is similar to transaction card2600 (FIG. 26) with the exception that transaction card 3100 omits coil2622. Secure transaction card 3100 includes first layer 3120 thatincludes electrically conductive coil 122, smartcard chip 2640, andcontrol circuit 2642. Layer 3110 is above layer 3120 and includes sensor2612. Layer 3130 is below layer 3120.

In operation, control circuit 2642 draws power from coil 122 when in thepresence of an interrogating radio frequency field, and then determineswhether to couple smartcard chip 2640 to coil 122 to effect atransaction. This is explained more fully below with reference to FIG.32.

FIG. 32 shows a diagram of a secure transaction card with activecontrol. FIG. 32 shows that secure transaction card 3100 has controlcircuit 2624 coupled to coil 122. When control circuit 2624 determinesthat contactless communications should be allowed and a transactionshould be effected, switch 2810 is closed using control signal 2812 asdescribed above with reference to FIG. 28.

FIG. 33 shows an exploded view of a secure transaction card with activecontrol. Secure transaction card 3300 includes layers 3310, 3320, and3330. First layer 3320 includes electrically conductive coils 122 and2622, control circuit 2624, and smartcard chip 3340. In embodimentsrepresented by FIG. 33, control circuit 2624 receives power from coil2622 when in the presence of an interrogating radio frequency field, andthen determines whether to conditionally couple smartcard chip 3340 tocoil 122, where the condition includes a state or sequence of statesread from sensor 2612.

Layer 3310 is above layer 3320 and includes hole 3312 to allowelectrical contacts on smartcard chip 3300 to be exposed on the surfaceof the card. Smartcard chip 3340 is an example of a dual interfacesmartcard chip that can communicate using a contact interface as well asa contactless interface. Layer 3310 also includes output device 3314. Insome embodiments, output device 3314 emits light, and in otherembodiments, output device 3314 emits sound. For example, output device3314 may be a light emitting diode or a speaker. Output device 3314 isshown coupled to control circuit 2624.

FIG. 34 shows a top view of the secure transaction card of FIG. 33.Electrical contacts on smartcard chip 3340 are exposed on the topsurface of secure transaction card 330. Similarly, sensor 2612 may beexposed on a surface of the card, as may be output device 3314.

FIG. 35 shows a flowchart of methods in accordance with variousembodiments of the present invention. In some embodiments, method 3500is performed by a user when interacting with a secure transaction cardin accordance with various embodiments of the present invention. Thevarious actions in method 3500 may be performed in the order presented,in a different order, or simultaneously. Further, in some embodiments,some actions listed in FIG. 35 are omitted from method 3500.

Method 3500 begins at 3510 in which a transaction card is pressed tocause a smartcard chip to make electrical contact with a conductivecoil. In some embodiments, this corresponds to a user press directly ona smartcard chip such as smartcard chip 140 (FIGS. 1, 4) or in thevicinity of a smartcard chip such as near area 812 (FIG. 9). In otherembodiments, this corresponds to a user pressing in an area (e.g., area1310; FIG. 13) that will cause a conductive strip to make a connectionto contacts coupled to an electrically conductive coil.

At 3520, the conductive coil is exposed to an interrogating radiofrequency field to provide power to the smartcard chip. In someembodiments, this corresponds to exposing electrically conductive coil122 to an interrogating radio frequency field generated by a readerdevice such as a point of sale device.

At 3530, the transaction card is released to break the electricalcontact between the smartcard chip and the electrically conductive coil.When the contact is broken, the smartcard chip is no longer able torespond to the interrogating radio frequency field.

FIG. 36 shows a flowchart of methods in accordance with variousembodiments of the present invention. In some embodiments, method 3600may be performed by a secure transaction card such any of those shown inprevious figures. Further, in some embodiments, method 3600 may beperformed by a control circuit such as control circuit 2642 (FIG. 26).Method 3600 is not limited by the type of system or entity that performsthe method. The various actions in method 3600 may be performed in theorder presented, in a different order, or simultaneously. Further, insome embodiments, some actions listed in FIG. 36 are omitted from method3600.

Method 3600 begins at 3610 in which a signal received from a coil placedin an interrogating radio frequency field is rectified to produce powerfrom a controller. This corresponds to rectifier 3030 (FIG. 30)rectifying a signal received from either coil 122 (FIG. 32) or 2622(FIG. 28).

At 3620, a sensor state is read. This corresponds to controller 3010(FIG. 30) reading the state of sensor 2612 (FIG. 26). In someembodiments, the sensor state is read multiple times, and a sequence isdetected.

At 3630, power is conditionally applied to a smartcard chip based on thestate of the sensor, or based on a sequence of states read from thesensor. For example, in some embodiments, controller 3010 connects asmartcard chip to a coil as in FIG. 28. Also for example, in someembodiments, controller 3010 tunes a coil to which the smartcard chip isalready connected as in FIG. 29.

Although the present invention has been described in conjunction withcertain embodiments, it is to be understood that modifications andvariations may be resorted to without departing from the spirit andscope of the invention as those skilled in the art readily understand.Such modifications and variations are considered to be within the scopeof the invention and the appended claims.

What is claimed is:
 1. A transaction card comprising: a firstelectrically conductive coil; a second electrically conductive coil; asensor to sense an environmental attribute; and a controller coupled toreceive power from the first electrically conductive coil when placed inan interrogating radio frequency field, and to conditionally couple thesecond electrically conductive coil to provide a communication pathbetween the transaction card and the interrogating radio frequency fieldin response to the environmental attribute.
 2. The transaction card ofclaim 1 wherein the sensor comprises a biometric sensor.
 3. Thetransaction card of claim 1 wherein the sensor comprises a fingerprintsensor.
 4. The transaction card of claim 1 wherein the sensor comprisesa proximity sensor.
 5. The transaction card of claim 1 wherein thesensor comprises a light sensor.
 6. The transaction card of claim 1wherein the sensor comprises a sound sensor.
 7. The transaction card ofclaim 1 wherein the sensor comprises a motion sensor.
 8. A transactioncard comprising: a first electrically conductive coil; a secondelectrically conductive coil; a sensor to sense an environmentalattribute; a controller coupled to receive power from the firstelectrically conductive coil when placed in an interrogating radiofrequency field; and a memory device having instructions encodedthereon, wherein the instructions, when executed by the controller,cause the controller to conditionally couple the second electricallyconductive coil to provide a communication path between the transactioncard and the interrogating radio frequency field in response to theenvironmental attribute.
 9. The transaction card of claim 8 wherein thesensor comprises a biometric sensor.
 10. The transaction card of claim 8wherein the sensor comprises a fingerprint sensor.
 11. The transactioncard of claim 8 wherein the sensor comprises a proximity sensor.
 12. Thetransaction card of claim 8 wherein the sensor comprises a light sensor.13. The transaction card of claim 8 wherein the sensor comprises a soundsensor.
 14. The transaction card of claim 8 wherein the sensor comprisesa motion sensor.
 15. A method comprising: rectifying a signal receivedfrom a first electrically conductive coil placed in an interrogatingradio frequency field to produce power for a controller in a transactioncard; reading a state of a sensor; and based on the state of the sensor,conditionally coupling a second electrically conductive coil to providea communication path between the transaction card and the interrogatingradio frequency field.
 16. The method of claim 15 wherein reading astate of a sensor comprises reading a state of a biometric sensor. 17.The method of claim 15 wherein reading a state of a sensor comprisesreading a state of a proximity sensor.
 18. The method of claim 15wherein reading a state of a sensor comprises reading a state of a lightsensor.
 19. The method of claim 15 wherein reading a state of a sensorcomprises reading a state of a sound sensor.
 20. The method of claim 15wherein reading a state of a sensor comprises reading a state of amotion sensor.